An estimated 69,000 adolescents and young adults (AYA) aged 15-39 years are diagnosed with incident cancer each year. The incidence of cancer within this age group is rare. Five-year survival from cancer is around 80%, resulting in untimely deaths for one-fifth of a young population. Health services research in the AYA population has been poorly studied due to AYA care falling in no man's land between pediatric and adult oncology, low participation in clinical trials, and lack of data of sufficient sample size for observational studies. To date, most of the relevant health services research on end of life care has focused in the Medicare population. End of life decisions are particularly difficult because our societal altruism to do what we can to save a young person from fatal cancer. To begin to understand what health care utilization is important in this population, we have the opportunity to evaluate the healthcare utilization an estimated 10,725 deaths among 257,400 AYA individuals in the largest available national claims data from UnitedHealth Group. Using an observational cohort study, our goal is to understand to current state of end of life care, defined as healthcare utilization within the last 30 and 365 days of AYA population with a cancer diagnosis and subsequent death due to cancer in 2003-2015, using this valuable resource. To address these goals we will: 1) Describe and compare the receipt of medical, surgical, and pharmacologic interventions in AYA population within the last 30 days and 365 days of life by evaluating temporal trends from 2003 to 2015; and 2) Describe and compare the receipt of medical, surgical and pharmacologic interventions in AYA population within the last 30 days and 365 days of life by evaluating U.S. geographic variation. We will use multivariate relative risk regression models to estimate risks of receipt of chemotherapy and hospitalization within 30 days of death as the primary analysis. Similar statistical analysis will be completed for secondary outcomes. Our proposal will address a significant and important need in health services research for end of life care. We propose to evaluate both 30 day and 365 day outcomes to more fully understand the oncology care continuum leading to cancer-related death and recognize temporal trend or geographic region. With the results from this study, we can lay the ground work for future end of life research in AYA population by providing the missing link What is currently happening in end of life care in AYA populations? With this information, future studies can develop relevant comparative effectiveness research questions on utilization of cancer treatment, develop interventions in the incorporation of palliative care in late stage AYA populations, and align patient preferences with cancer care. Using national claims-based data, we will have the largest sample of deaths in AYA population to study national trends over a 13 year period. We have the opportunity to make a critically important contribution to the field of oncology care of young cancer patients. We have the opportunity to overcome a significant gap in understanding end of life care within the AYA population.